KETO DIET

hi everyone, i’m planning on starting the keto diet at some point soon as ive noticed people achieve fast results. i’m looking to lose about 20 kilos, how long should it take (approx)? any tips about what or what not to eat, any vitamins/supplements i may need to take, or any other general information would be much appreciated as i dont know too much about it yet. thanks for your help :))